1. Field of the Invention
The present disclosure relates to an information processing apparatus which is used to perform settlement or a commercial transaction, and more particularly, to an information processing apparatus for a credit card, a debit card, electronic money, or the like.
2. Description of the Related Art
In recent years, the size and power consumption of a settlement processing apparatus used to perform settlement or a commercial transaction have been reduced with a remarkable development, which results in an increase in the use of portable settlement processing apparatuses. While the portable settlement processing apparatus has convenience of easy carrying, the chance for the portable settlement processing apparatus to be accessed by people other than regular device users increases, and thus there is an increasing risk that confidential information, such as an encryption key or personal information, serving as information to be protected which is stored in a settlement processing apparatus, is stolen. Proposals for protecting information to be protected from fraudulent actions have been made.
Japanese Patent Unexamined Publication No. 2013-003979 discloses an information processing apparatus including first and second circuit boards disposed within the apparatus body so as to be separated from and face each other, electronic components respectively disposed on the opposing surfaces of the first and second circuit boards, and a shielding member that surrounds outer circumferential portions of the first and second circuit boards. The above document discloses that the information processing apparatus further includes a detection circuit as a tamper detection unit and that the detection circuit is operated to erase data stored in a memory and prevent a fraudulent action from occurring when a hole is formed in a shielding member, provided with a detection line, by using a drill or the like.
Japanese Patent Unexamined Publication No. 2008-033593 discloses a data storage device including a memory, electric wires, a detection unit, and a control unit. The memory is provided within a housing. The electric wires are disposed at sufficiently small intervals with respect to the length or width of the surface of the housing so as to cover substantially the entire surface of the housing and are substantially narrow with respect to the length or width of the surface of the housing. The detection unit detects the disconnection of the electric wire. The control unit erases data stored in the memory when the disconnection of the electric wire is detected. The above document discloses that a tampering action such as the destruction or opening of the housing is monitored and that data is erased with respect to the tampering action.
However, the above-mentioned information processing apparatus of the related art is limited so that an open detection circuit, a CPU, a flash ROM, and an S-RAM are mounted on the same substrate. In the data storage device disclosed in Japanese Patent Unexamined Publication No. 2008-033593, the arrangement of circuit components between front and back surfaces on a main board is arbitrary, but six sides of the entire main board have to be surrounded by a protection board, which results in the necessity of a large space volume in a secure region. In order to improve security, a reduction in the dimension of a secure unit is one of the useful elements. However, the above-mentioned information processing apparatus of the related art has a problem that it is difficult to further reduce the size of a portion constituting the secure region.